Abstract
The need for organs for donation is far greater than organ availability. In the last decade this has led to restructuring and investment in the organ donation programme with political and public support. The majority of transplanted organs are retrieved from patients dying on an intensive care unit, and the wish to consider organ donation as a normal part of end-of-life care has led to considerable pressure on clinicians to adhere to the large amount of practical and ethical guidance being published to achieve this. There has not been universal acceptance of the guidance by critical care clinicians, and this paper explores some of the concerns related to the practicalities of the evolving changes in management of potential organ donation patients within intensive care.
Introduction
Since the first kidney transplant in 1954 there have been numerous developments that have contributed to the widely accepted practice of various organ donation transplant programmes that are in place throughout the world today. The rapid advances in medicine, especially in transplant surgery, immunology and critical care, have meant that successful transplants can be performed for recipients that would not have been possible or considered even a short time ago. And yet, despite this, there are still over 8000 people on the UK transplant waiting list, with only just over a third likely to receive a transplant each year leading to approximately three people each day dying for want of a suitable organ. Not only does this realization have a considerable impact on those waiting for a donation but it also has huge financial implications; transplants are very cost-effective with each successful kidney transplant saving the National Health Service (NHS) over £24,000 per annum. 1
Inevitably, there has been the wish, and pressure, to maximize the number of potential donors to meet demand. The first living transplant donation in the UK was in 1960, preceding donation from dead donors; the rate is still rising and now accounts for nearly one-third of all transplants. The majority of organs from dead donors still come from patients who have suffered a catastrophic brain injury and have been pronounced brain stem dead on the intensive care unit (ICU) following a series of formal tests. Introduction of legislation to reduce injury from trauma (notably the compulsory wearing of seatbelts) has led to a reduction in available donors and as a result there has been considerable effort to increase organ donation from other dead patients. Since 2000, there has been a steady and dramatic rise in successful transplants from patients where medical treatment is withdrawn and the organs are retrieved after the heart has stopped. This latter practice is increasingly gaining acceptance but is not universally accepted by all critical care clinicians, and has resulted in the publication of much guidance on ethical and practical issues.
The first substantial document that has helped current transplant practice was published in 2003 by the Department of Health setting up key aims for organ and tissue transplantation over the next 10 years. Saving Lives, Valuing Donors, a transplant framework for England, set out a framework for increasing donation by encouraging people to donate organs and tissues, raising the quality and effectiveness of the transplant programme and to urge hospitals to put in place the appropriate infrastructure to allow this to happen, but it did not put in place any substantial plans to change the organ donation programme. 2 This occurred with the publication in 2008 by the Department of Health, supported by the Scottish and the Welsh Assembly Governments, from the Organ Donation Taskforce called Organs for Donation. 3 This aimed to ‘resolve the problems that result from the lack of a structured and systematic approach to organ donation, and to a lesser extent organ transplantation’. There were 14 recommendations to ensure that ‘organ donation should become usual rather than unusual and be a normal part of end of life care for appropriate patients’. This view is also shared by the General Medical Council which states that ‘if a patient is close to death and their views cannot be determined, you should be prepared to explore with those close to them whether they had expressed any views about organ or tissue donation, if donation is likely to be a possibility. You should follow any national procedures for identifying potential organ donors and, in appropriate cases, for notifying the local transplant coordinator’. 4 Among the proposals was that there should be a UK-wide Organ Donation Organisation under the responsibility of the NHS Blood and Transplant service, resolution of outstanding ethical, legal and professional issues (with the formation of a UK Donation Ethics Committee), restructuring of transplant coordinators and transplant teams, removal of financial disincentives for hospitals facilitating organ donation, mandatory training for staff and regular local audit of donation activity. As a result of these recommendations each critical care unit has embedded in it a specialist nurse for organ donation (SNOD) whereas, previously, there had been one transplant coordinator covering many hospitals. In addition, each Trust or Health Board has a Clinical Lead for Organ Donation whose responsibility is to establish training and local structural re-arrangements in order to maximize organ donation potential. Each organization also has an Organ Donation Committee with a broad spectrum of membership to ensure their region complies with the recommendations and to monitor local activity and report to the Trust or Health Board via the governance process. There is also a National Organ Retrieval Service. This new arrangement has been in place for a couple of years, and certainly in Wales there seems to have been a significant improvement in organ donation rates although it is too early to say whether this be will sustainable. 5
Diagnosing death
The issues of organ donation and diagnosis of death are intertwined but it is important to establish what the definition of death is within the context of organ donation and the complexities of the ICU. The most reliable diagnosis of death is livor mortis, the third pathological stage when the tissues break down leading to the outward appearance of purple staining of lividity (postmortem discolouration) and putrefaction. Organ donation aside, waiting for this to occur before diagnosis is neither desirable nor practical and so there have evolved many other ways of trying to diagnose death. The Romans were aware of the potential for premature burial and would make a loud performance around the body, conclamatio (from which we get the word ‘clamour’), for a period of eight days in order to try to wake the person if he was suffering from something that may be mimicking death. Certainly there are many conditions, notably cholera, plague, typhus, typhoid, catalepsy and hypothermia that have all caused misdiagnosis of death. In 1740, the Danish anatomist and physician Jacob Winslow published his Dissertation on the Signs of Death recognizing ‘death is certain, since it is inevitable, but also uncertain, since its diagnosis is sometimes fallible’. 6 The surgeon-in-chief of Napoleon's armies, Baron Dominique Jean Larrey, introducing a system of triage on the battlefield, used a mirror to hold in front of the mouth of dead soldiers looking for signs of misting but this was not sensitive enough to detect shallow breathing. 7 With the invention of the stethoscope in 1816, it was now possible to detect breath sounds, the absence of which still is fundamental to the diagnosis of death on many occasions today. 8 By 1846 the stethoscope was also being used to detect the absence of heart sounds that again is used as a sign of death today. Nevertheless, the fear of premature burial was still an issue in Victorian times, with waiting mortuaries and some elaborate graves equipped with air vents and signalling devices.
Until the middle of the 20th century, the cardiopulmonary standard, the absence of heart sounds and breath sounds over several minutes, was the basis on which death was diagnosed. However, alongside this traditional standard, there came the need to develop a new one because the advances in critical care now allowed artificial mechanical ventilation of the lungs in a group of patients with severe intracranial pathology who would have previously died from stopping breathing. This led to the development of the concept of neurological death as a marker of death alongside the traditional cardiopulmonary one.
Donation after brain stem death
Professional guidance
With the introduction of mechanical ventilation and the advances in critical care medicine it became apparent that there were a group of patients who had suffered catastrophic brain injuries, usually as a result of trauma or bleeding, who were dependent on the ventilator and who would never recover consciousness. In 1959, two French neurologists called this state le coma dépassé – ‘the state beyond coma’. 9 Other physicians were also recognizing that there was a need to distinguish between two groups of brain-injured ventilated patients: those less incapacitated who were not dead, and those in whom the level of brain injury was so severe that in effect those patients in a coma dépassé were already dead. In 1968, a committee at Harvard Medical School published criteria with the purpose ‘to define irreversible coma as a new criterion for death’, and with the aim to be able to withdraw mechanical ventilation before the heart had stopped beating. 10 The tests included unreceptivity and unresponsitivity, no movements or breathing, no reflexes, confirmatory data, no confounding factors and repeated after 24 hours. This was to form the basis of the current criteria for brain stem testing, and in 1976, in the UK, a Conference of the Medical Royal Colleges met ‘to establish diagnostic criteria of such rigour that on their fulfilment the mechanical ventilator can be switched-off, in the secure knowledge that there is no chance of recovery’. These criteria were published in the British Medical Journal establishing conditions for considering diagnosis of brain death, and the tests for confirming brain death. 11 This allowed withdrawal of artificial support on confirmation of brain death on the basis that there was no chance of recovery, not on the basis that the patient was dead, but it introduced the concept that these patients were as good as dead (and would certainly die in due course). Further clarification came in the form of a memorandum published in 1979 from a Conference of the Medical Royal Colleges which stated that ‘it is the conclusion of the conference that the identification of brain death means that the patient is dead, whether or not the function of some organs, such as a heart beat, is maintained by artificial means’. 12 This paved the way for the procurement of organs for transplant from the beating heart cadaver. Further to this, in 1995, the Working Group of the Medical Royal Colleges proposed the more scientifically rigorous term – ‘brain stem death’. 13 The most recent published guidance, in 2008, coinciding with the Organ Donation Taskforce recommendations to clarify professional, ethical and legal issues, is from the Academy of the Medical Royal Colleges, A code of practice for the diagnosis and confirmation of death, providing guidance on death following the irreversible cessation of brain stem function and death following cessation of cardiorespiratory function. 14 Although the document acknowledges that there is no statutory legal definition of death in the UK, it states that the Courts of England and Northern Ireland have adopted the ‘brain death criteria’ following the 1976 Conference of the Medical Royal Colleges as part of the law for the diagnosis of death.
Brain stem death testing
The brain stem lies at the base of the skull above the foramen magnum and connects the spinal cord to the midbrain, cerebellum and cerebral hemispheres. Located within the brain stem are the arousal, cardiovascular and respiratory centres, the nuclei for 10 of the 12 cranial nerves, the sensory and motor nerve pathways between the cerebral hemispheres and the spinal cord, and the pathway for the autonomic nervous system. The basis of the tests is to demonstrate the absence of reflexes associated with pathways through the brain stem.
Before the tests are done there are a number of preconditions that have to be met. First of all, there should be no doubt that the patient's condition is due to irreversible brain damage of known aetiology, and potentially reversible causes of coma have been excluded. The patient must be deeply comatose, unresponsive with his lungs being artificially ventilated. There should be no evidence that this state is due to depressant drugs, hypothermia or potentially reversible cardiovascular, endocrine or metabolic disturbances. Other causes for the absence of respiratory effort, such as depressant drugs, muscle relaxants and profound neuromuscular weakness must also be excluded.
Once these preconditions are met then the tests involve demonstrating the absence of brain stem reflexes, notably the absence of those functions controlled by the cranial nerves. The pupils are fixed and do not respond to a sharp change in light intensity. There is no corneal reflex. The oculo-vestibular reflexes are absent (ice cold water injected into the outer ear to touch the ear drum does not cause any eye movement). No motor response within the cranial nerve distribution can be elicited by adequate stimulation within any somatic area (absence of response to supraorbital pressure). There should not be any response to a suction catheter passed down into the trachea to stimulate the bronchial tree (absent cough reflex), and there should be no gag reflex with stimulation of the posterior pharynx with a spatula. If there has been no response to these tests then the apnoea test is done. Apnoea is the absence of breathing and the trigger for breathing is determined by the level of carbon dioxide in the blood. The test determines whether there is any respiratory effort made by the patient when artificial ventilation is stopped and the level of carbon dioxide in the blood has risen to a level where breathing would be occurring in the absence of brain stem death. If there is no response to any of the tests, since the definition of death should be regarded as the irreversible loss of the capacity for consciousness combined with the irreversible loss of the capacity to breathe, the patient is declared to have fulfilled the criteria to establish brain stem death. 15
Two doctors who have been fully registered for more than five years undertake the tests on two occasions, and one must be a consultant. The doctors must be competent in the conduct and interpretation of brain stem testing, and neither must have any clinical conflict of interest nor be a member of the transplant team. Death is not confirmed until the second set of tests has been completed although the legal time of death is taken as the time that the first set of tests indicates death due to the absence of brain stem reflexes. In the UK, the clinical tests are considered adequate to establish brain stem death, and the need for neurophysiology tests (such as an electroencephalogram), and tests for cerebral blood flow or brain tissue perfusion are not considered necessary.
If the patient could potentially be an organ or tissue donor the family is approached to explore the patient's prior wishes regarding organ donation. If the family consent to donation proceeding, the SNOD arranges the appropriate tests necessary for transplantation to be done while awaiting the arrival of the transplant retrieval team, and the critical care staff maintain the patient on the necessary organ support until the patient is transferred to the operating theatre for organ retrieval to occur. The process is classified as donation after brain death (DBD). If the condition of the patient is not suitable for organ donation to be considered, or if the family refuse to go ahead with donation, artificial ventilation is stopped and the heart will stop beating soon afterwards due to a lack of oxygen.
Donation after cardiac death
Prior to the introduction of brain stem death as the definition of death in 1979 in the UK, allowing organ transplant to be taken from patients whose hearts were still beating (DBD), all organ transplants came from non-heart beating donors, now known as donation after cardiac (or circulatory) death (DCD).
Brain stem dead donors led to better results as the organs were perfused with oxygenated blood until the point of organ retrieval, and so non-heart beating donors were generally no longer considered. However, a growing discrepancy between the demand for organs and their availability from brain stem dead donors has led to a re-examination of using non-heart beating donors which in the UK now account for over one-third of dead organ donors. 16
Donation after cardiac death is grouped by the 1995 Maastricht Classification. 17 Groups 1 and 2, patients who are dead on arrival and are dead after unsuccessful resuscitation attempts, respectively, are uncontrolled and therefore are rarely suitable for organ donation but are suitable for heart valves and corneas. Group 3, where cardiac arrest occurs after withdrawal of life support in patients who are not brain stem dead and group 4, where cardiac arrest occurs after brain stem death are controlled situations within an ICU involving the timely withdrawal of life-supporting interventions to allow organ donation to proceed after the heart has stopped beating. These are the two main patient groups from whom organs for kidney, liver, lungs and heart transplants are retrieved after circulatory death.
Group 5, the unexpected cardiac arrest in a hospital patient, was added in 2000 and, being uncontrolled, is only suitable for tissue donation.
Within intensive care, DCD is considered in those situations where the decision has been made to withdraw life-saving treatment being provided for a ventilated patient on the basis that it is no longer being of benefit and is not in their interest to continue with it (futility), or to comply with an advanced directive. The decision to withdraw treatment must be made on an assessment of the benefits of continuing care and must not be influenced by matters of potential organ donation; there must be no actual or perceived conflicts of interest. To achieve this it is best practice to have separate discussions with the family, often with the critical care specialist explaining the reasons for treatment withdrawal and then sometime later the SNOD should approach them to enquire about the possibility of organ donation after death.
Once a decision to withdraw support has been made, and the family is willing for organ donation to be considered, then treatment withdrawal is delayed for discussion to be had with transplant centres to see if the patient's organs and tissues would be suitable for donation. If they are, then withdrawal is further delayed until the logistics necessary for retrieval to occur have been arranged. This includes availability of the retrieval team to be in the operating theatre to which the body will be transferred, after death has been pronounced, the permission of the HM Coroner where necessary and for the tests necessary for tissue typing and transplantation to have been processed. Once everything is in place for retrieval to proceed, then treatment is withdrawn, usually by stopping the medical interventions that are supporting the cardiovascular and respiratory systems. The SNOD records the time of treatment withdrawal, and the time that the blood pressure and oxygen levels fall below a certain level for the reason that if the dying process is prolonged, then the organs will no longer be suitable for donation because of a lack of adequate perfusion. Finally, the time at which asystole commences, defined as ‘absent or near absent electrical activity of the heart associated with no evidence of cardiac output (i.e., absent peripheral pulsation/arterial line trace)’, is recorded. After five minutes of monitoring, asystole death can be certified once a medical practitioner has ascertained the patient is pulseless, the patient is apnoeic, there is absence of pupil light reflexes, the patient shows no motor response to supraorbital pressure and the patient has absent corneal reflexes. The time of death is recorded as the time at which these criteria are fulfilled. The body is then transferred immediately to the operating theatre for retrieval to occur.
Although historically DCD was in practice before DBD the continuation of medical treatment for these patients when organ donation is being considered, for whom withdrawal of treatment would be the normal practice when it was clear that ongoing care was of no perceived benefit, has raised some concerns for critical care staff. These are largely addressed in the guidance Legal Issues relevant to non-heart beating organ donation published by the Department of Health in 2009. 18 It states that ‘maintenance of life-sustaining treatment may be considered to be in the best interests of someone who wanted to be a donor if it facilitates donation and does not cause them harm or distress, or place them at significant risk of experiencing harm or distress’. It goes on to say that ‘taking blood and testing blood or serum samples may therefore be considered to be in the best interests of someone who wanted to be a donor’. Since some of these patients often have life-saving treatment started in the emergency department, there has been concern that transferring these patients to a critical care unit (where admission is usually reserved for those patients for whom there is considered a realistic chance of surviving with appropriate management) solely to facilitate organ donation is not legal or ethical. However, the guidance advises ‘delaying the withdrawal of treatment and changing a patient's location may be considered to be in the best interests of someone who wanted to be a donor if this facilitates donation and does not cause the person harm or distress, or place them at significant risk of experiencing harm or distress’. Clearly, the emphasis is that it is appropriate for interventions to be done to facilitate organ donation as long as they do not involve a significant risk of causing the patient harm or distress. There is no definition of best interests but the implication is that the best interests of the patients are served by doing what is necessary to permit a pre-existing altruistic wish to help others by donating their organs for transplantation, helping others benefit from their death. Further guidance published in 2011 by the Academy of Medical Royal Colleges from the UK Donation Ethics Committee, called An Ethical Framework for Controlled Donation after Circulatory Death, provides similar guidance within a framework for optimizing the chances of donation after cardiac death. 19
Despite these changes in practice surrounding treatment withdrawal, it must remain the case that life-saving interventions must only be performed with the intention for the benefit of the patient and not solely for the purpose of organ donation. In the 1980s patients were admitted to the ICU in Exeter with serious intracranial pathology for mechanical ventilation purely for the purpose of organ donation and not for their benefit. 20 This policy, known as elective ventilation, was deemed illegal later and is still the case. However, a recent editorial in the British Medical Journal commenting on the recent National Institute for Health and Clinical Excellence guideline on organ donation for transplantation stated ‘the new guidance implies that an admission to an ICU and institution of life-saving treatment should be provided for most patients judged to have untreatable, rapidly lethal conditions, while determining their wishes with respect to donation’. 21,22 It is likely that most critical care staff will find this unacceptable; the role of intensive care medicine is to institute life-saving treatment when there is a reasonable expectation of patient survival, without causing undue pain, distress or lack of dignity. It would not be appropriate to start such treatment in dying patients especially when their views are unknown. The use of limited critical care beds for such a group would also deprive other patients who would benefit from intensive care management. It remains unlawful.
Presumed consent
The kidney donor card was introduced in the UK in 1971, and the NHS Organ Donor register in 1994 and yet, despite all the investment and increasing emphasis on donation, the demand is still greatly in excess of supply. Noting that countries that have a system of presumed consent have higher donation rates per head of population, the Welsh Government has decided to introduce a similar system in Wales. It is planned to have a system of presumed consent whereby it would be presumed that a patient was willing for organs to be used for transplantation unless that patient had registered a prior objection, but it would be within a soft opt-out process whereby the family would still have the final decision. To that effect a White Paper was published in 2011, with a consultation period that ended at the end of January 2012. 23 The proposal is to present a bill to the Welsh Government in 2012, for its approval to be gained by 2013, and then for Wales to adopt a system of presumed consent in 2015. However, although critical care specialists support organ donation and are fundamental to the success of any programme since nearly all potential donors are managed on an ICU, the Faculty of Intensive Care Medicine and the Welsh Intensive Care Society have expressed concern regarding the implementation of the proposals. There is the belief that the public have not been given enough insight into the process surrounding organ donation within intensive care for a presumption of consent to be considered valid. Presumed consent is ethically meaningless since valid consent requires enough information to be provided to an individual for a reasoned decision to be reached, and it cannot be assumed that in this situation that is the case. For consent to be valid it has to be informed, not presumed, and therefore under the soft opt-out system proposed, organ donation would have to be acknowledged as being non-consensual. There is concern that promoting presumed consent by comparing donation rates with other nations who have a similar system in place is disingenuous since there are many other confounding issues that all affect donation rates. The high rates of organ donation are often used as a justification for introducing a system of presumed consent, and yet the President of the Spanish National Transplant Organisation is explicit in saying that presumed consent is not the reason for the success of the Spanish system (which has the highest donor rate in the world). 24 He attributed the success of the Spanish system to investment in and organization of the infrastructure of the transplant services, always approaching the families and making sure that they have the last decision on whether donation should proceed. Furthermore, relatives of patients on the ICU have to be positive that any decision that a critical care specialist makes regarding end-of-life decisions are done so on the basis of treatment failure and is completely independent of issues regarding organ donation. There is the risk that presumed consent for organ donation may lead to the perception that there is a possible conflict of interest, by limiting or instituting therapies purely for reasons of organ donation. There is no proposal in the White Paper for a systematic research assessment of the impact of introducing presumed consent. This is essential to ensure that any changes in organ donation can be attributed to either the introduction of a new system or to the ongoing benefits of the current investment and infrastructure already in place. The research methods need to be rigorous enough to ensure that such an assessment would be published in peer-reviewed journals and withstand critical scientific scrutiny. Finally, organ donation rates are highest in the countries that have an adequate number of intensive care beds. The UK, and Wales in particular, have the lowest number of intensive care beds per capita than any European country, and it is the view of the specialists that this needs to be addressed before any additional legislation should be considered.
An independent report from The Organ Donation Taskforce in 2008, The Potential Impact of an opt-out system for Organ Donation in the UK, stated that ‘there was a clear consensus in recommending that an opt-out system should not be introduced in the UK at the present time. The Taskforce concluded that such a system has the potential to undermine the concept of organ donation as a gift, to erode trust in NHS professionals and the Government and negatively impact on organ donation numbers. It would distract attention away from essential improvement to systems and infrastructure and from the urgent need to improve public awareness and understanding of organ donation. Furthermore, it would be challenging and costly to implement successfully. Most compelling of all, we found no convincing evidence that it would deliver significant increase in the number of organs donated.’ 25
Conclusion
There is no doubt that an increase in organ donation rates is necessary to meet demand. The evolving definition of death in ICUs has allowed transplantation to proceed from dead donors. Additional proposals to increase organ donor rates further by presumed consent or elective ventilation are unlikely to be universally accepted by critical care specialists.